Vegetative compatibility groups within Fusarium oxysporum f.sp. lini from Linum usitatissimum (flax) wilt nurseries in western Canada

2001 ◽  
Vol 79 (7) ◽  
pp. 836-843 ◽  
Author(s):  
S I Mpofu ◽  
K Y Rashid

Following the discovery of substantial differences in the development and severity of Fusarium wilt in Linum usitatissimum L. (flax) wilt nurseries in western Canada, a study of the population structure of Fusarium oxysporum f.sp. lini (Bolley) Snyd. & Hans using vegetative compatibility analysis was initiated. Vegetative compatibility was determined using nitrate non-utilizing mutants. From a total of 105 isolates, 74 were assigned to 12 vegetative compatibility groups (VCG 0440-04411), 22 were not compatible with any other isolates and 9 did not produce mutants. The populations of F. oxysporum f.sp. lini in Fusarium wilt nurseries in western Canada were significantly different. There was a predominant VCG in each of the nurseries, which was either nonexistent or not common in other nurseries, VCG 0440 in Indian Head, 0441 in Treherne, 0442 in Morden-80, 0443 in Saskatoon, and 0444 in Morden-60. There were only three overlapping VCGs; VCG 0440 was common to Morden-60 and Indian Head and VCGs 0442 and 0444 were common to Morden-60 and Morden-80. The differences in disease development and severity observed previously may be due to the differences in the population structure of the pathogen. These findings have significant implications for the approaches to breeding for Fusarium wilt resistance in flax.Key words: Fusarium oxysporum f.sp. lini, flax, Fusarium wilt, genetic diversity, vegetative compatibility.

1992 ◽  
Vol 70 (6) ◽  
pp. 1211-1217 ◽  
Author(s):  
T. R. Gordon ◽  
D. Okamoto

Two hundred isolates of Fusarium oxysporum, 100 from each of two different locations, were collected from agricultural field soils in the San Joaquin Valley of California. These isolates comprised 39 different vegetative compatibility groups. Based on the frequency distribution of vegetative compatibility groups, populations of F. oxysporum at the two collection sites were different. At least one isolate from each vegetative compatibility group was examined for polymorphisms in mitochondrial DNA. A total of 41 differences in mitochondrial DNA were identified, each of which was treated as a character and scored as present or absent in each strain. There were 11 unique combinations (haplotypes) of the 41 characters. Three mitochondrial DNA haplotypes were common to both sites and the remaining eight occurred at only one of the two sites. Isolates in the same vegetative compatibility group were always associated with the same mitochondrial DNA haplotype. Many isolates in different vegetative compatibility groups also shared a common mitochondrial DNA haplotype. Fusarium oxysporum f.sp. melonis, cause of Fusarium wilt of muskmelon, was associated with the same mitochondrial DNA haplotype as eight vegetative compatibility groups of F. oxysporum that were not pathogenic to muskmelon. This result may indicate that either the pathogen was a recent derivative of nonpathogenic strains at the same location or avirulent strains have been derived from the pathogen. Key words: anastomosis, fungi, heterokaryon, Fusarium wilt.


1990 ◽  
Vol 41 (5) ◽  
pp. 863 ◽  
Author(s):  
VM Brake ◽  
KG Pegg ◽  
JAG Irwin ◽  
PW Langdon

Wilt of bananas (Musa spp.), caused by Fusarium oxysporum Schlect. f. sp. cubense(E. F. Smith) Snyd. &Hans. (FOC), has a long history in subtropical Queensland, where it has destroyed many plantations of cv. Lady finger. Cavendish (AAA) clones are now being attacked in subtropical Queensland. Vegetative compatibility was used to subdivide Australian populations of FOC. One hundred and fortyeight isolates were placed in six vegetative compatibility groups (VCGs). VCG was correlated with virulence on specific cultivars in the field. All putative race 1 isolates belonged to VCGs 0124 and 0125 and with one exception, isolates in this group were recovered only from cultivars susceptible to race 1. Evidence is presented which suggests that wilt in Cavendish cultivars in Queensland is due to the previous widespread distribution of Cavendish competent strains (VCGS 0120,0129) in plantings of Lady finger, which is the major Australian race 1 susceptible cultivar.


Plant Disease ◽  
2005 ◽  
Vol 89 (3) ◽  
pp. 237-240 ◽  
Author(s):  
Matias Pasquali ◽  
Flavia Dematheis ◽  
Giovanna Gilardi ◽  
Maria Lodovica Gullino ◽  
Angelo Garibaldi

Fusarium oxysporum f. sp. lactucae, the causal agent of Fusarium wilt of lettuce, has been reported in three continents in the last 10 years. Forty-seven isolates obtained from infected plants and seed in Italy, the United States, Japan, and Taiwan were evaluated for pathogenicity and vegetative compatibility. Chlorate-resistant, nitrate-nonutilizing mutants were used to determine genetic relatedness among isolates from different locations. Using the vegetative compatibility group (VCG) approach, all Italian and American isolates, type 2 Taiwanese isolates, and a Japanese race 1 were assigned to the major VCG 0300. Taiwanese isolates type 1 were assigned to VCG 0301. The hypothesis that propagules of Fusarium oxysporum f. sp. lactucae that caused epidemics on lettuce in 2001-02 in Italian fields might have spread via import and use of contaminated seeds is discussed.


2014 ◽  
Vol 94 (2) ◽  
pp. 445-449 ◽  
Author(s):  
S. D. Duguid ◽  
K. Y. Rashid ◽  
E. O. Kenaschuk

Duguid, S. D., Rashid, K. Y. and Kenaschuk, E. O. 2014. Prairie Thunder flax. Can. J. Plant Sci. 94: 445–449. Prairie Thunder, medium-maturing oilseed flax (Linum usitatissimum L.), was released in 2006 by Agriculture and Agri-Food Canada, Morden Research Station, Morden, Manitoba. Developed from the cross AC Watson/FP1043 made in 1995, Prairie Thunder was evaluated in the Flax Cooperative Trials (2002–2004) before being registered in 2006. Prairie Thunder's desirable combination of improved agronomic traits, seed quality and superior wilt (Fusarium oxysporum Schlecht. f. sp. lini (Bolley) Snyder & Hansen) resistance should make this cultivar useful for producers and the flax industry.


2007 ◽  
Vol 155 (1) ◽  
pp. 61-64 ◽  
Author(s):  
A. Catti ◽  
M. Pasquali ◽  
D. Ghiringhelli ◽  
A. Garibaldi ◽  
M. L. Gullino

2020 ◽  
Vol 158 (2) ◽  
pp. 495-509 ◽  
Author(s):  
P. Ndayihanzamaso ◽  
P. Karangwa ◽  
D. Mostert ◽  
G. Mahuku ◽  
G. Blomme ◽  
...  

Abstract Banana is a staple food and cash crop grown in East and Central Africa (ECA). The main banana varieties grown in ECA are the East African highland bananas (EAHB), although dessert/beer bananas such as Sukari Ndizi, Kayinja (Pisang Awak) and Gros Michel are also produced due to their high value at local markets. The Fusarium wilt fungus Fusarium oxysporum f. sp. cubense (Foc) causes disease of susceptible dessert/beer bananas, which significantly reduces yields. Banana Fusarium wilt is managed by excluding the pathogen from disease-free areas and by planting disease-resistant varieties in infested fields. Six phylogenetically closely-related vegetative compatibility groups (VCGs) of Foc, VCGs 0124, 0125, 0128, 01212, 01220 and 01222 are present in ECA, which all group together in Foc Lineage VI. Rapid and accurate detection of Foc Lineage VI strains is thus important to prevent its spread to disease-free areas. In this study, molecular markers specific to Foc Lineage VI were therefore developed. Primer sets were then combined in a multiplex PCR assay, and validated on a worldwide population of 623 known Foc isolates, other formae speciales and non-pathogenic Fusarium oxysporum isolates. The Foc Lineage VI multiplex PCR was used to identify Foc isolates collected in banana fields at five locations in Uganda and Tanzania. Foc Lineage VI DNA was detected at a concentration as low as 0.1 ng/μl, both in the absence and presence of banana DNA, and can therefore be used as an accurate diagnostic tool for Foc Lineage VI strains.


2008 ◽  
Vol 6 (1) ◽  
pp. 22-32 ◽  
Author(s):  
Axel Diederichsen ◽  
Tatiana A. Rozhmina ◽  
Ljudmilla P. Kudrjavceva

Germplasm of 153 flax (Linum usitatissimum) accessions from 24 countries held at Plant Gene Resources of Canada (PGRC) was evaluated for resistance to fusarium wilt (Fusarium oxysporum), anthracnose (Colletotrichum lini) and pasmo (Septoria linicola). The screening was conducted at the All-Russian Flax Research Institute (VNIIL) at Torzhok, Russia, over 3 years for fusarium wilt and anthracnose, and over 2 years for pasmo. A disease severity index ranging from 0% (no infection) to 100% (heavy infection) was calculated based on observations after artificial inoculation with the pathogens in the greenhouse (fusarium wilt) or in field nurseries (anthracnose and pasmo). The average disease severity index for fusarium wilt was 56.6 ± 34.4% (range 0–100.0%), for anthracnose 59.8 ± 8.1% (range 43.8–83.9%) and for pasmo 74.2 ± 11.8% (range 27.3–100.0%). The variation of disease severity indices among the years and within each accession was highest for fusarium wilt. Higher than average resistance for all three diseases was found in accessions from East Asia, while germplasm from the Indian subcontinent showed considerably lower than average resistance. Germplasm from North America and South America (mostly linseed) displayed above average resistance to fusarium wilt, while European accessions (mostly fibre flax) showed lower than average resistance to this disease. The different resistance levels reflected the improvements made by plant breeding and differences in the environments under which the germplasm accessions evolved. Accessions with potential use in linseed and fibre flax breeding were identified.


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